Tetsuya Mizuguchi is best known for Rez, Space Channel 5 and Lumines. He's made lots of Lumines spin-offs like Lumines Live! and Lumines II. Key words: Lumines. We haven't seen a new game from Mizuguchi for a while, but he confirmed to Kotaku that, yes, he's working on a new IP. Says Mizuguchi:

Yes, I'm working on a new IP.

We've heard from sources that it may be an Xbox 360 title. Wonder what it is...